Sisters, a Sibling's Keeper

A study done as part of Brigham Young University's Flourishing Families project found that the presence of a sister can help decrease negative emotions like loneliness or depression.

Dr. Jennifer Hartstein, an adolescent and child psychologist, joined co-anchor Erica Hill on "The Early Show" Thursday morning to explain why having a sister can make children happier.

Hartstein says that having a sister around can create a nice buffer. A sister can make a child feel like they have someone they can relate to - a feeling that parents often can't provide. The major point of happiness comes in a sister to sister relationship. Brothers are great siblings as well, but Harstein explains that the gender role may come into play.

"(Girls) tend to be a much more social, interactive kind of role in a different way than a brother would. So, it's really also sister to sister. That's important to think about, is sisters are learning from their older sisters or younger sisters, how to be caring, how to look out for, how to watch out for the emotional needs of one another," said Hartstein.

Though having a sister can help create emotional support, it can also create a field for competition. Siblings who don't get along can create more aggressive behavior in relationships later on.

"There can be competition all the way," said Hartstein. "Competition can also be healthy. It does teach you how to work through conflicts, how to negotiate, how to navigate those problems. And that's so important. One of the really important things about siblings."

Parents should take an active role in promoting positive interactions. Harstein stresses on how big of a role communication plays in having a positive relationship between siblings and parents.

"As a family you want a nurturing environment because the more you have that the more love and respect there will be," said Hartstein.

When it comes to fame-having a celebrity sister can actually be a very great experience. For sisters like Venus and Serena Williams, it can provide ongoing support as they are experiencing similar things and can share their experiences together. Though they could be considered one another's biggest competition, they are also each other's greatest source of support.

Often times one sister is more famous than another. In this case, it makes sense that jealous would occur, which would certainly make an impact on the sisterly relationship. From time to time, one sister may follow in the other's footsteps, and the other will "take care" of them. If jealousy does take over, the bond of sisterhood should overcome that.

Hartstein suggests parents help their children create a lifetime bond by having them participate in activities together, and encouraging communication. There will no doubt be fights, and it's okay for sisters to yell and scream and slam doors as long as they come back around and discuss the fight later.

Stress the importance of talking it out. Model the behavior that you would like them to do, the more supportive an environment they're in, the more they will learn to support each other.